.TITLE	ISIZE
; AUTHOR:	MARTY PORTNER
;		WORLD BOOK-CHILDCRAFT, INC.
; FUNCTION SUBROUTINE TO FIND THE LENGTH OF A CHARACTER VARIABLE.
; CALLING FORMAT:
;
;		VAR=ISIZE(STR)
; THE VALUE OF VAR WILL BE THE NUMBER OF CHARACTERS IN 'STR' .
;
; DEFAULTS SUPPLIED:		NONE
 
	.IDENT	*ISIZE3*
 
	.PSECT	$$STRG,RO,I,CON,LCL
 
ISIZE::
 
	CMPB	#1,@R5		;ARGUMENT THERE ??
	BNE	OUT$$		;NO, EXIT
	MOV	2(R5),R0	;ELSE, MOVE ADDR OF 'STR' TO R0
1$:	TSTB	(R0)+		;FIND ZERO BYTE
	BEQ	2$		;WHEN FOUND, EXIT LOOP.
	BR	1$		;ELSE, CONTINUE SEARCH
2$:	SUB 	2(R5),R0	;CALCULATE LENGTH
	DEC	R0		;
OUT$$:	RTS	PC		;RETURN THIS VALUE
 
	.END			;